The Squirrel Hill Tunnel lies 3 3/4 miles ahead on Interstate 376 West. This sign states that the maximum vertical clearance through the tunnel is 15'6" and that flammable liquids and explosives are prohibitied in it. (Photo taken 9/5/15).

Take Exit 78B to Forest Hills. (Photo taken 9/5/15).

For the next 2 1/2 miles, Interstate 376 West will traverse a steep downgrade. Trucks are alerted that they will be restricted to 35 mph. (Photo taken 9/5/15).

This overhead sign warns that trucks over 15'6" in height will see lights flashing 3/4 mile ahead, meaning they are prohibited from using the Squirrel Hill Tunnel and must exit before it. (Photo taken 9/5/15).

Interstate 376 West at mile marker 78. (Photo taken 9/5/15).

Interstate 376 West as the downgrade continues for another 1 1/2 miles. (Photo taken 9/5/15).

Interstate 376 West at mile marker 77.5. (Photo taken 9/5/15).

Take Exit 77 to Kennywood Park and the Pittsburgh Zoo & PPG Aquarium. (Photo taken 9/5/15).

Trucks are reminded here that if they're hauling any flammable liquids or explosives, they must take Exit 77 since it's the final exit before the Squirrel Hill Tunnel. (Photo taken 9/5/15).

Interstate 376 West as it enters the Pittsburgh city limits. (Photo taken 9/5/15).

Take Exit 74 to Chatham University and Sandcastle. (Photo taken 9/5/15).

Take Exit 72B or 70C to PNC Park and Heinz Field via the North Shore. Take Exit 71A or 70D to access downtown parking if you choose to walk across the Clemente Bridge to PNC Park and Heinz Field. (Photo taken 9/5/15).

Interstate 376 West at the overheight vehicle detector approaching the tunnel. If the lights on this overhead sign are flashing, your vehicle is overheight for the tunnel and you will be required to turn around. (Photo taken 9/5/15).

Near mile marker 72.5, we see the first of several Emergency Pull-Offs on Interstate 376 West. It gets pretty tight and congested ahead, and as a result there is no shoulder. That makes these pull-offs necessary. (Photo taken 9/5/15).

Interstate 376 West at Exit 72B: To Interstate 579 - Blvd of the Allies / Liberty Bridge (Photo taken 9/5/15).

Approaching Exit 71B, we see another Emergency Pull-Off in the distance. (Photo taken 9/5/15).

This sign lists the distances to the three upcoming exits to downtown Pittsburgh. (Photo taken 9/5/15).

A third Emergency Pull-Off on Interstate 376 West, at mile marker 71.5 on the left.
(Photo taken 9/5/15).

A fourth Emergency Pull-Off exists just past the previous one, on the right. (Photo taken 9/5/15).

Interstate 376 West at Exit 71B: Second Ave (Photo taken 9/5/15).

Interstate 376 West at mile marker 71. (Photo taken 9/5/15).

Interstate 376 West at Exit 71A: Grant Street (Photo taken 9/5/15).

Interstate 376 West approaching Exit 70C - 1/2 mile. Because the right lane is an exit only lane, it essentially means that I-376 West is reduced to one lane here in downtown Pittsburgh for a brief time. (Photo taken 9/5/15).

Interstate 376 West approaching Exit 70C - 1/4 mile. Be in the left lane here to remain on I-376 West to the Fort Pitt Bridge and Airport. (Photo taken 9/5/15).

Interstate 376 West approaching Exit 69C, as we prepare to cross the Fort Pitt Bridge into the Fort Pitt Tunnel. I-376 West traffic is carried on the lower deck. (Photo taken 9/5/15).

An attempted shot of Interstate 376 West on the lower deck of the Fort Pitt Bridge. You will need to make a quick lane change to the right here to access Exit 69C ahead. Be in the two leftmost lanes to remain on I-376 West. (Photo taken 9/5/15).

Interstate 376 West at Exit 69C: PA 837 North / To PA 51 - West End. Sorry about how this one turned out. (Photo taken 9/5/15).

Interstate 376 West as it prepares to enter the Fort Pitt Tunnel, immediately at the south/west end of the Fort Pitt Bridge. (Photo taken 9/5/15).

An attempted view of Interstate 376 West inside the Fort Pitt Tunnel. (Photo taken 9/5/15).

Take Exit 69A to Mt Lebanon and Uniontown. (Photo taken 9/5/15).

Interstate 376 West at Exit 69A: US 19 South - Banksville Rd (Photo taken 9/5/15).

Just past Exit 20, the speed limit decreases to 55 mph as we begin to approach the second toll plaza on Interstate 376 West. (Photo taken 9/5/15).

Interstate 376 West 1 mile from the toll plaza. (Photo taken 9/5/15).

Interstate 376 West at mile marker 19. (Photo taken 9/5/15).

This time, cars will owe $2.15. Added to the $1.25 from the first toll plaza, the total cost at this time was $3.40 for cars to drive the entire 16.5-mile length of the tolled portion of Interstate 376. (Photo taken 9/5/15).

Approaching the toll plaza, EZ Pass tagholders are reminded to keep to the left. Cash customers should stay right. In case you hadn't noticed, there is no ticket system on the tolled portion of Interstate 376. (Photo taken 9/5/15).

View of the second toll plaza on Interstate 376 West. (Photo taken 9/5/15).